INSTRUCTIONS TO CANDIDATES Use black ink or black ball-point pen. Do not use gel pen or correction fluid.

Transcription

1 Surname Centre Number Candidate Number Other Names 0 GCSE 4462/02 SCIENCE A/CHEMISTRY CHEMISTRY 1 HIGHER TIER A.M. THURSDAY, 12 June hour For s use Question Maximum Mark Mark Awarded ADDITIONAL MATERIALS In addition to this paper you will need a calculator and a ruler INSTRUCTIONS TO CANDIDATES Use black ink or black ball-point pen. Do not use gel pen or correction fluid. Total 60 Write your name, centre number and candidate number in the spaces at the top of this page. Answer all questions. Write your answers in the spaces provided in this booklet. If you run out of space, use the additional page(s) at the back of the booklet, taking care to number the question(s) correctly. INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. You are reminded that assessment will take into account the quality of written communication used in your answer to questions 4 and 10. The Periodic Table is printed on the back cover of the examination paper and the formulae for some common ions on the inside of the back cover. SM*(S )

2 2 Answer all questions. 1. (a) The table below shows some properties of three elements in the Periodic Table. Element Melting point ( C) Boiling point ( C) Appearance Malleable or brittle? Electrical conductivity aluminium shiny solid malleable good silicon shiny solid brittle semiconductor phosphorus white solid brittle poor Describe how the information in the table shows that silicon is difficult to classify as a metal or a non-metal. [2] (b) Give the symbol of the element which is found in Group 2 and Period 3 of the Periodic Table. [1]... (c) (i) The chemical formula of copper(ii) nitrate is Cu(NO 3 ) 2. Give the number of nitrogen atoms in the formula Cu(NO 3 ) 2. [1]... (ii) Give the chemical formula of silver oxide. [1]... (d) Nano-scale silver particles are added to socks to reduce the effects of smelly feet. Recent research has found that these particles can easily leak into waste water during washing. (i) State the property of nano-scale silver particles that makes them useful in socks.... [1] (ii) Suggest a reason why some scientists are concerned about nano-scale silver particles entering waste water. [1] 7 ( )

3 3 2. (a) The graphs below show the melting points and boiling points of Group 2 elements Melting point ( C) Boiling point ( C) Be Mg Ca Sr Ba 0 Be Mg Ca Sr Ba Group 2 elements Group 2 elements Use the information in the graphs to describe the trends, if any, in the melting point and boiling point of Group 2 elements. [2] Melting point Boiling point... (b) The table below describes the reactions of Group 2 elements when added to cold water. Group 2 Element beryllium magnesium calcium strontium Reaction when added to cold water no reaction very slow reaction fairly vigorous reaction very fast reaction Barium lies below strontium in Group 2. State, giving a reason, how you would expect barium to react with cold water. [2] 4 ( ) Turn over.

4 4 3. (a) Iron is extracted in the blast furnace. Iron ore, limestone, coke and hot air are the raw materials. iron ore, limestone and coke waste gases hot air iron hot air slag (i) Give the reason for adding each of the following to the furnace: I coke; [1] II limestone. [1] (ii) I Balance the symbol equation that represents the main reaction occurring in the furnace. [1] Fe 2 O 3 + CO Fe + CO 2 II Give the chemical name of the substance which is reduced in the furnace. [1] ( )

5 (b) 5 The graph below shows how the tensile strength of iron alloys changes with the percentage of carbon present Tensile strength (MPa) Percentage of carbon present (%) (i) Describe how the tensile strength changes as the percentage of carbon present increases. [2] (ii) The table below shows the percentage of carbon present in some iron alloys. Alloy of iron Percentage of carbon present in the alloy (%) wrought iron 0.1 mild steel 0.3 high-carbon steel 0.9 cast iron 3.6 Use the information in the table and the graph to name the alloy which has the lowest tensile strength. [1]... 7 ( ) Turn over.

6 6 4. Explain, giving examples, why plastics have replaced traditional materials such as iron, glass and wood for making many everyday things. [6 QWC] 6 ( )

7 7 5. The diagram below shows some reactions of dilute hydrochloric acid. colourless zinc chloride solution and gas A zinc carbonate blue copper(ii) chloride solution base E dilute hydrochloric acid magnesium colourless solution B and gas C sodium hydroxide solution colourless solution D (a) Give the names of each of the substances A to E. [5] A... B... C... D... E... (b) Give the chemical formula of zinc chloride. [1]... 6 ( ) Turn over.

8 8 6. The graphs below show the results of research on the effect of water fluoridation on the teeth of children aged 12 years in the United States. (DMFT = number of decayed, missing or filled teeth) mean DMFT Percentage (%) of children drinking fluoridated water % drinking fluoridated water Mean DMFT Year ( )

9 9 (a) Calculate the percentage decrease in the mean DMFT between 1967 and [2] Percentage decrease in the mean DMFT =... % (b) Apart from drinking water, give one other source of fluoride which could reduce tooth decay. [1] (c) In your opinion, do the advantages of the fluoridation of drinking water outweigh the disadvantages? Explain your reasoning. [2] Opinion (Yes or No)... Explanation ( ) Turn over.

10 10 7. Three students individually investigated the mass of copper formed when increasing amounts of magnesium powder were added to 50 cm 3 of copper(ii) sulfate solution. stirrer 50 cm 3 copper(ii) sulfate solution magnesium powder copper powder Each pupil added 0.10 g of magnesium to 50 cm 3 of copper(ii) sulfate solution and stirred the mixture until no more magnesium remained. They filtered, dried and weighed the copper formed. They repeated the experiment using 0.15, 0.20 and 0.25 g of magnesium powder and a new 50 cm 3 of copper(ii) sulfate solution each time. The results are shown below. Mass of magnesium added (g) Student A Mass of copper formed (g) Student Student B C Mean The graph opposite shows the masses of copper that should be formed. (a) On the same grid plot the mean mass of copper formed against the mass of magnesium added. Draw a suitable line. [3] ( )

11 expected results 0.5 Mass of copper formed (g) Mass of magnesium added (g) (b) Describe the main difference between the expected graph and the one plotted using the experimental results. [1] (c) Suggest two possible reasons for the difference in the graphs. [2] ( ) Turn over.

12 12 (d) On Anglesey there is a large copper mine called Parys Mountain. Unwanted rock from the mining process has been dumped forming waste tips. As rainwater passes through the waste tips it dissolves copper salts. One of the salts is copper(ii) sulfate. During the 18 th century large shallow pits were dug all over the mountain. These filled with rainwater. Scrap iron was placed into the water and after a few months the pits were drained and a copper-rich solid sludge was collected. Explain the reaction taking place in the pits. [3] (e) Copper is a good electrical conductor and is therefore used to make electrical wiring. Give a different property of copper and one use which relies on this property. [2] Property... Use ( )

13 13 8. (a) A small minority of scientists believe that it is changes in solar activity (i.e. changes in the brightness and warmth of the sun) that causes global warming. The graphs below show the changes in solar activity and atmospheric temperature since solar activity temperature 0.5 Solar activity 0 Temperature change ( C) Year Using the information from the graphs, state how well the evidence supports the argument that solar activity is the cause of global warming. [2] (b) Most scientists believe the main cause of global warming is the increase in carbon dioxide levels in the atmosphere. (i) State the main cause of this increase in carbon dioxide levels. [1]... (ii) Describe one method of reducing current atmospheric carbon dioxide levels. [1] 4 ( ) Turn over.

14 14 9. The table below shows the relative supply of and demand for some fractions obtained from a sample of crude oil from the North Sea. % mass of fraction Fraction In crude oil (supply of) Market demand (demand for) C 1 -C C 5 -C C 9 -C C 13 -C C 17 -C C 21 -C C (a) Give a reason why market demand for the C 5 -C 8 fraction is high. [1] (b) The supply of the C 5 -C 8 fraction is less than the market demand. Explain how oil companies overcome this problem. [2] (c) One hydrocarbon found in the C 1 -C 4 fraction is propane. Propane burns in air forming carbon dioxide and water. Balance the symbol equation that represents this reaction. [1] C 3 H 8 + O 2 CO 2 + H 2 O 4 ( )

15 The diagram below shows an electrolysis cell used in the extraction of aluminium. oxygen gas anode cathode molten aluminium oxide and cryolite molten aluminium Outline the industrial extraction of aluminium. [6 QWC] END OF PAPER 6 ( ) Turn over.

16 16 BLANK PAGE PLEASE DO NOT WRITE ON THIS PAGE ( )

17 17 BLANK PAGE PLEASE DO NOT WRITE ON THIS PAGE ( ) Turn over.

18 18 Question number Additional page, if required. Write the question number(s) in the left-hand margin. ( )

19 19 FORMULAE FOR SOME COMMON IONS POSITIVE IONS NEGATIVE IONS Name Formula Name Formula Aluminium Ammonium Barium Calcium Copper(II) Hydrogen Iron(II) Iron(III) Lithium Magnesium Nickel Potassium Silver Sodium Zinc Al 3+ + NH 4 Ba 2+ Ca 2+ Cu 2+ H + Fe 2+ Fe 3+ Li + Mg 2+ Ni 2+ K + Ag + Na + Zn 2+ Bromide Carbonate Chloride Fluoride Hydroxide Iodide Nitrate Oxide Sulfate Br 2 CO 3 Cl F OH I NO 3 O 2 2 SO 4 ( ) Turn over.

20 20 PERIODIC TABLE OF ELEMENTS 1 2 Group H 4 He 2 Hydrogen Helium 7 Li 3 9 Be B 12 C 6 14 N 7 16 O 8 19 F 9 20 Ne 10 Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon 23 Na Mg Al Si 31 P S Cl Ar Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon K 40 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rb 88 Sr Y Zr Nb Mo Tc Ru Rh 106 Pd Ag Cd In Sn Sb 128 Te I Xe 54 Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon 133 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 86 Caesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon 223 Fr Ra Ac 89 Francium Radium Actinium Key: Mass number Atomic number A X Element Symbol Z Name ( )